Capacitive-type touch panel and touch-point detecting method thereof

• US 8,487,899 B2
• Filed: 07/14/2009
• Issued: 07/16/2013
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: Coretronic Corporation
• Original Assignee: Coretronic Corporation
• Inventors: Chen, Chun-Yu
• Primary Examiner(s): Wong, K.
• Application Number:
  US12/502,242
• Publication Number:
  US 20100090980A1
• Time in Patent Office: 1,463 Days
• Field of Search: None
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A capacitive-type touch panel and a touch-point detecting method thereof are provided. The capacitive-type touch panel includes a plurality of first-dimension sensing lines and a plurality of second-dimension sensing lines arranged crossing over one another and in a matrix. When detecting a first touch point and a second touch point existed on the capacitive-type touch panel at the same time by scanning the capacitive-type touch panel, locations of the first touch point and the second touch point are determined according to detected currents in the first-dimension sensing lines and the second-dimension sensing lines. Capacitances of each of the first-dimension sensing lines are gradually decreased along a first direction, and capacitances of each of the second-dimension sensing lines are gradually decreased along a second direction.

Claims

1. A capacitive-type touch panel configured for detecting a touch point when an object touches the capacitive-type touch panel, the capacitive-type touch panel comprising:

a plurality of first-dimension sensing lines, wherein the first-dimension sensing lines are arranged in parallel with one another and extend along a first direction, each of the first-dimension sensing lines comprises a plurality of first-dimension capacitive pads arranged along the first direction and each of the first-dimension capacitive pads has a capacitance when no touch point occurs on the first-dimension sensing line, the capacitances being different from each other and gradually decreased along the first direction; and

a processor configured for scanning the first-dimension sensing lines and determining a location of the touch point on the first-dimension sensing lines according to a result of the scanning.

2. The capacitive-type touch panel as claimed in claim 1, wherein each of the first-dimension sensing lines further comprises a plurality of first-dimension conductive line segments, each first-dimension conductive line segment is electrically coupled between the corresponding two adjacent first-dimension capacitive pads, and touch areas of the first-dimension capacitive pads of each of the first-dimension sensing lines are gradually decreased along the first direction.

3. The capacitive-type touch panel as claimed in claim 1, wherein the processor determines the location of the touch point on the first-dimension sensing lines by scanning a current in the first-dimension sensing lines when the object touches the capacitive-type touch panel.

4. A capacitive-type touch panel configured for detecting a touch point when an object touches the capacitive-type touch panel, the capacitive-type touch panel comprising:

a plurality of first-dimension sensing lines, wherein the first-dimension sensing lines are arranged in parallel with one another and extend along a first direction, each of the first-dimension sensing lines comprises a plurality of first-dimension capacitive pads arranged along the first direction and each of the first-dimension capacitive pads has a capacitance when no touch point occurs on the first-dimension sensing line, the capacitances being different from each other and gradually decreased along the first direction;

a processor configured for scanning the first-dimension sensing lines and determining a location of the touch point on the first-dimension sensing lines according to a result of the scanning associated with the first-dimension sensing lines; and

a plurality of second-dimension sensing lines, wherein the second-dimension sensing lines are arranged in parallel with one another and cross over the first-dimension sensing lines, each of the second-dimension sensing lines comprises a plurality of second-dimension capacitive pads arranged along a second direction and each of the second-dimension capacitive pads has a capacitance when no touch point occurs on the second-dimension sensing line, the capacitances being different from each other and gradually decreased along the second direction, and wherein the processor is further configured for scanning the second-dimension sensing lines and determining a location of the touch point on the second-dimension sensing lines according to another result of the scanning associated with the second-dimension sensing lines.

5. The capacitive-type touch panel as claimed in claim 4, wherein each of the second-dimension sensing lines further comprises a plurality of second-dimension conductive line segments, each second-dimension conductive line segment is electrically coupled between the corresponding two adjacent second-dimension capacitive pads, and touch areas of the second-dimension capacitive pads of each of the second-dimension sensing lines are gradually decreased along the second direction.

6. The capacitive-type touch panel as claimed in claim 4, wherein the processor determines the location of the touch point on the second-dimension sensing lines by scanning a current in the second-dimension sensing lines when the object touches the capacitive-type touch panel.

7. The capacitive-type touch panel as claimed in claim 4, wherein each of the first-dimension sensing lines further comprises a plurality of first-dimension conductive line segments, each first-dimension conductive line segment is electrically coupled between the corresponding two adjacent first-dimension capacitive pads, and touch areas of the first-dimension capacitive pads of each of the first-dimension sensing lines are gradually decreased along the first direction.

8. The capacitive-type touch panel as claimed in claim 5, wherein each of the first-dimension sensing lines further comprises a plurality of first-dimension conductive line segments, each first-dimension conductive line segment is electrically coupled between the corresponding two adjacent first-dimension capacitive pads, and touch areas of the first-dimension capacitive pads of each of the first-dimension sensing lines are gradually decreased along the first direction.

9. The capacitive-type touch panel as claimed in claim 4, wherein the processor determines the location of the touch point on the first-dimension sensing lines by scanning a current in the first-dimension sensing lines when the object touches the capacitive-type touch panel.

10. A touch-point detecting method of a capacitive-type touch panel adapted for detecting a plurality of touch points on the capacitive-type touch panel, the capacitive-type touch panel comprising a plurality of first-dimension sensing lines and a plurality of second-dimension sensing lines arranged in a matrix, the first-dimension sensing lines being arranged in parallel with one another and the second-dimension sensing lines being arranged in parallel with one another, the touch-point detecting method of the capacitive-type touch panel comprising:

scanning the first-dimension sensing lines and the second-dimension sensing lines; and

when detecting a first touch point and a second touch point existed on the capacitive-type touch panel at the same time, determining locations of the first touch point and the second touch point according to detected currents in the first-dimension sensing lines and the second-dimension sensing lines, wherein each of first-dimension sensing lines comprises a plurality of first-dimension capacitive pads arranged along a first direction and each of the first-dimension capacitive pads has a first capacitance when no touch point occurs on the first-dimension sensing line, the first capacitances being different from each other and gradually decreased along the first direction, each of second-dimension sensing lines comprises a plurality of second-dimension capacitive pads arranged along a second direction and each of the second-dimension capacitive pads has a second capacitance when no touch point occurs on the second-dimension sensing line, the second capacitances being different from each other and gradually decreased along the second direction.

11. The touch-point detecting method of the capacitive-type touch panel as claimed in claim 10, wherein the step of determining the locations of the first touch point and the second touch point according to the detected currents in the first-dimension sensing lines and the second-dimension sensing lines when detecting the first touch point and the second touch point existed on the capacitive-type touch panel at the same time comprises:

obtaining a first coordinate value and a second coordinate value of the first touch point and the second touch point respectively on the first-dimension sensing lines according to the detected currents in the first-dimension sensing lines;

obtaining a third coordinate value and a fourth coordinate value of the first touch point and the second touch point respectively on the second-dimension sensing lines according to the detected currents in the second-dimension sensing lines; and

putting the first coordinate value, the second coordinate value, the third coordinate value, and the fourth coordinate value in pairs according to the detected currents in the first-dimension sensing lines and the second-dimension sensing lines to obtain the locations of the first touch point and the second touch point.

12. The touch-point detecting method of the capacitive-type touch panel as claimed in claim 11, wherein the step of putting the first coordinate value, the second coordinate value, the third coordinate value, and the fourth coordinate value in pairs according to the detected currents in the first-dimension sensing lines and the second-dimension sensing lines to obtain the locations of the first touch point and the second touch point comprises one of the followings:

when the current obtained for detecting the first touch point is larger than the current obtained for detecting the second touch point in the first-dimension sensing lines, selecting one of the third coordinate value and the fourth coordinate value which is closer to a start point of the first direction as a second-dimension location of the first touch point;

when the current obtained for detecting the first touch point is smaller than the current obtained for detecting the second touch point in the first-dimension sensing lines, selecting one of the third coordinate value and the fourth coordinate value which is closer to an end point of the first direction as a second-dimension location of the first touch point;

when the current obtained for detecting the first touch point is larger than the current obtained for detecting the second touch point in the second-dimension sensing lines, selecting one of the first coordinate value and the second coordinate value which is closer to a start point of the second direction as a first-dimension location of the first touch point; and

when the current obtained for detecting the first touch point is smaller than the current obtained for detecting the second touch point in the second-dimension sensing lines, selecting one of the first coordinate value and the second coordinate value which is closer to an end point of the second direction as a first-dimension location of the first touch point.